A driving method of an organic light emitting display device includes sensing temperatures of a plurality of areas included in a pixel unit and, when a temperature difference between the respective areas is less than a predetermined reference value, outputting first data that is input from outside. When the temperature difference between the respective areas is equal to or greater than the reference value, the method includes generating second data by changing a grayscale of the first data such that the temperatures of the respective areas are similar to each other, and outputting the second data.